You can create a list with the names, and the number of occurrences
allowed. For example:

John 2
Tony 1

Name this range, e.g. LookupList

Then, in the data validation dialog box, use a formula that refers to
this list. For example:

=COUNTIF($B$1:$B$16,B1)<=VLOOKUP(B1,LookupList,2,0 )

andrewm wrote:
Hi - the validation rule works but
how do I make it specific for the names specified. Other names (eg
John) can be entered in more than once.

andrewm




--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html